Here's a thought...

What happened in Italy on October 10, 1582, in England on September 9, 1752, and in Russia on February 2, 1918 ?

Actually, nothing happened, which is highly unusual...

In fact, October 5th through the 14th in 1582 did not exist in history at all !!! At least if you abide by the Gregorian Calendar. Another interesting fact is that not everyone in Europe abided by the new-fangled Gregorian calendar; it took until September of 1752 for England and 1918 for Russia to accept the change!